1. Technical Field
The present invention relates to a layered structure. More specifically, the present invention relates to a layered structure including a lower structure and an upper structure joined to the lower structure via a pivot member, and functioning to hold up a portion of the upper structure with the pivot member as an axis.
2. Related Art
A known image reading/recording apparatus is provided with a reading unit and a recording unit in a layered state, for example. This type of apparatus is sometimes configured such that the reading unit provided on the upper portion serves as a cover for the recording unit provided on the lower portion.
In other words, when accessing the inside of the recording apparatus, e.g. when replacing the ink cartridge of the recording unit or removing a recording medium that is jammed in the feeding path, the scanner serving as the cover is lifted to expose the inside of the recording unit. When opening a reading unit that serves as such a cover, the reading unit is desirably held in the lifted state while a user replaces the ink cartridge or the like on the inside.
When closing the opened reading unit serving as the cover, the reading unit desirably does not freely drop to the closed state, since the scanner is high-precision machinery and not merely a cover. Therefore, when closing the reading unit, a mechanism is provided to decrease the speed of the fall or to stop the reading unit momentarily in the middle of the fall.
JP-A-2001-125233 discloses a structure provided with a rail mechanism that guides the upper ends of a series of stays that support the movable cover of the photo processing apparatus, and an avoidance mechanism that is provided on the rail mechanism to guide the upper ends of the stays to take a different path when moving backward than when moving forward. With this structure, when closing the cover, the cover is momentarily held at the mid-point of the lowering, to prevent the cover from being closed too quickly.
JP-A-2005-345050 discloses a structure that decreases the closing speed of a large cooking range cover. This prevents a large and heavy cooking range cover from falling too quickly.
JP-A-2006-044073 discloses a structure provided with a linking member having a guide groove with a portion curved for a lid having a pin. With this structure, when closing the lid, the closing can be stopped or slowed.
As described above, a mechanism is desired that can slow the opening or closing of a lid or cover, particularly the closing. The various mechanisms described above, however, have complicated configurations with many components, resulting in problems such as a lack of durability and high cost. Furthermore, shock absorbing mechanisms using elastic bodies or liquids, such as a gas damper, have expensive components and gradually lose their effectiveness with repeated use.